Writing mystery stories are more critical and interesting as well. The main concept of mystery story must be revealing a suspense to the readers. While creating such a suspense, the author has to become successful in the inclusion of some kind of a distraction which makes the readers to wonder if the reality is revealed.
A character is the soul of a story. It leads the story in its path. Without a character, the story can't move in its concept. The character should be built with all the potential attributes from the ground up so that they get attached to the reader's hearts.